Application of a simplified HPLC assay for the determination of phylloquinone (vitamin K1) in animal and plant food items

The lack of precise data in food composition tables demands intensive investigation of phylloquinone content in human food, for the purpose of nutritional intake assessment and support of anticoagulant drug therapy. The determination of small phylloquinone amounts requires sensitive and selective detection methods. Based on a RP-HPLC assay using post-column derivatization and fluorescence detection, and combined with a liquid-liquid sample clean-up, a rapid and routinely usable assay is presented. The application to foods is shown in the items of milk (0.36 ± 0.07 μg/100 g), other dairy products (yoghurt, 0.34 ± 0.04 μg/100 g), eggs (1.85 ± 0.99 μg/100 g), edible oils (from 0.97 to 112 μg/100 g), oatmeal (4.07 ± 0.35 μg/100 g), broccoli (195 ± 40 μg/100 g), cauliflower (12.0 ± 6.1 μg/100 g), carrots (5.94 ± 3.39 μg/100 g) and potatoes (1.62 ± 1.21 μg/100 g). The samples cover a range of foods, from those of fairly low to those of high phylloquinone content. High precision and wide application range both offer valuable instruments for food analysis and construction of current food composition and nutrition tables in the future.